In recent years, a metal-oxide-semiconductor field-effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), an injection enhanced gate transistor (IEGT), and the like are used as semiconductor devices for power control. The MOSFET is a unipolar-type semiconductor device using either electrons or holes as carriers, and accordingly, there is no built-in potential therein in a conduction direction. For this reason, while the MOSFET can be electrically conducted even with an applied voltage lower than that of a bipolar-type semiconductor device such as the IGBT or IEGT, the conduction capability thereof is lower than that of the bipolar-type semiconductor device.